The stereoselective synthesis of fimsbactin A, a siderophore of the human pathogen Acinetobacter baumannii, was established. Based on this synthetic route, various fimsbactin stereoisomeric analogues were generated and tested for their iron delivery activity for A. baumannii. This investigation revealed that the fimsbactin uptake machinery in this bacterium was indeed highly stereoselective in substrate recognition.A synthetic method to prepare spiro[4,n]alkyl[b]indoles (n = 4-6) efficiently that relies on the gold(I) and Brønsted acid mediated spirocyclization of 2- and 3-indolyl-tethered 1,4-enyne acetates at room temperature and open to air is described.Purification and collection of industrial products from oil-water mixtures are commonly implemented processes. However, the efficiencies of such processes can be severely influenced by the presence of emulsifiers that induce the formation of small oil droplets dispersed in the mixtures. Understanding of this emulsifying effect and its counteractions which occur at the oil/water interface is therefore necessary for the improvement of designs of these processes. In this paper, we investigated the interfacial mechanisms of protein-induced emulsification and the opposing surfactant-induced demulsification related to corn oil refinement. At corn oil/water interfaces, the pH-dependent emulsifying function of zein protein, which is the major storage protein of corn, was elucidated by the surface/interface-sensitive sum frequency generation (SFG) vibrational spectroscopy technique. The effective stabilization of corn oil droplets by zein protein was illustrated and correlated to its ordered amide I group at the oil/water interface. Substantial decrease of this ordering with the addition of three industrial surfactants to corn oil-zein solution mixtures was also observed using SFG, which explains the surfactant-induced destabilization and coalescence of small oil droplets. Surfactant-protein interaction was then demonstrated to be the driving force for the disordering of interfacial proteins, either by disrupting protein layers or partially excluding protein molecules from the interface. The ordered zein proteins at the interface were therefore revealed to be the critical factor for the formation of corn oil-water emulsion.Necrosis targeting and imaging has significant implications for evaluating tumor growth, therapeutic response, and delivery of therapeutics to perinecrotic tumor zones. Hypericin is a hydrophobic molecule with high necrosis affinity and fluorescence imaging properties. To date, the safe and effective delivery of hypericin to areas of necrosis in vivo remains a challenge because of its incompatible biophysical properties. To address this issue, we have developed a biodegradable nanoparticle (Hyp-NP) for delivery of hypericin to tumors for necrosis targeting and fluorescence imaging. The nanoparticle was developed using methoxy poly(ethylene glycol)-b-poly(ε-caprolactone) and hypericin by a modified solvent evaporation technique. The size of Hyp-NP was 19.0 ± 1.8 nm from cryo-TEM and 37.3 ± 0.7 nm from dynamic light-scattering analysis with a polydispersity index of 0.15 ± 0.01. The encapsulation efficiency of hypericin was 95.05% w/w by UV-vis absorption. https://www.selleckchem.com/products/bromopyruvic-acid.html After storage for 30 days, 91.4% hypericin was retained in Hyp-NP with nearly no change in hydrodynamic size, representing nanoparticle stability. In an ovarian cancer cell line, Hyp-NP demonstrated cellular internalization with intracellular cytoplasmic localization and preserved fluorescence and necrosis affinity. In a mouse subcutaneous tumor model, tumor accumulation was noted at 8 h postinjection, with near-complete clearance at 96 h postinjection. Hyp-NP was shown to be tightly localized within necrotic tumor zones. Histological analysis of harvested organs demonstrated no gross abnormalities, and in vitro, no hemolysis was observed. This proof-of-concept study demonstrates the potential clinical applications of Hyp-NP for necrosis targeting.We report a new analytical approach to model the transient diffusion and adsorption kinetics of a surfactant at a liquid/liquid interface using dynamic interfacial tension data. The developed model combined with the Frumkin/Langmuir isotherm is used to reproduce the experimental data of dynamic interfacial tension and predict the surfactant diffusion coefficient from a bulk solution to an interface and its adsorption kinetics. Experimental data of the dynamic interfacial tension of toluene and heptol solutions at various concentrations of asphaltenes (a natural surfactant) were employed to examine the ability of the developed model to regenerate the dynamic interfacial tension data. The model enabled us to estimate the apparent diffusion coefficient and adsorption kinetics of asphaltenes at different concentrations. The results showed that the diffusive migration of asphaltene toward an oil/water interface decreases at its higher concentrations and increases at higher concentrations of an aliphatic solvent such as n-heptane. Furthermore, the results reveal that the adsorption rate of asphaltenes at the interface increases at higher concentrations of surfactants and the aliphatic solvent. The developed analytical model finds applications in the prediction of the diffusion and adsorption kinetics of surfactants using dynamic interfacial tension data.Natural gas (NG) is an interesting primary fuel; its larger-scale use is hindered by the difficulties of storing it under high pressures or low temperatures; a viable alternative is its storage via physisorption in porous materials. Most NG adsorption studies have focused on adsorption of pure methane, its primary component. Here we investigate the influence of heavier alkanes commonly found in NG (propane, ethane) on the adsorption process. We present the results of extensive molecular dynamics simulations of mixtures of methane-propane and methane-ethane at T = 300 and 400 K and P = 0-1500 bar in slit-shaped pores with interlayer spacings H = 8-20 Å. We observed that heavier hydrocarbons adsorb preferentially but remain mobile, which is promising for the intended application. We also solved a common problem with simulations of molecules with high adsorption affinity the difficulty to determine their partial pressure. We developed an Arrhenius-type relationship allowing the calculation of these partial pressures from relationships between energy distributions of the different molecules in the simulations in conditions where a direct determination of these is impractical or impossible.